OpenSE4 0.6.0

OpenSE4 is an open-source engine for Space Empires IV Deluxe. It plays the classic game on your own installed copy of Space Empires IV Deluxe and contains nothing from the original game.

OpenSE4 is not affiliated with, endorsed by or sponsored by the game's publishers.

What changed since 0.5.0

This release brings the computer players closer to the original's. The original game was watched under a read-only debugger over seven 100-turn games: every empire's state, battles and base placements, recorded turn by turn. The rules found there are now in OpenSE4.

• Fleets and movement.
  • The ministers' movement orders now last one turn, as in the original, so warships are free for new tasks each turn.
  • Ships recruited into a fleet chase it until they join.
  • Fleets are no longer formed around troop transports or empty carriers.
• Targets and exploration follow the original's rules: which enemy planets are worth attacking, and which ships go exploring.
• Budget and scrapping.
  • The construction budget accounts for what the queues are already spending.
  • Colony ships no longer count toward the maintenance limit.
  • Over the limit, the computers scrap their oldest ship design, as the original does. They used to scrap their bases first.
  • So computer players now keep their bases, and found more colonies.
• Combat: a piece blocked by an obstacle now tries to slide around it, as in the original.
• Saves: like the original, a saved game no longer keeps the mood changes waiting for the next turn.

Compared with the original's computer players over 100 turns:

• the time they spend in their short-term defence state, and their research per colony, now fall within the original's spread from game to game;
• bases per empire went from about 0.1 to about 0.35 (the original: 0.4–0.6 in most games).

Saved games from earlier versions can't be loaded (save format 6), and every player in a network game needs 0.6.0 (protocol 4).

Downloads

File	For
OpenSE4-0.6.0-windows-x86_64-setup.exe	64-bit Windows 10 and 11: the installer
OpenSE4-0.6.0-windows-x86_64.zip	64-bit Windows 10 and 11: the same programs to run from any folder
OpenSE4-0.6.0-linux-x86_64.tar.gz	64-bit Linux with glibc 2.34 or later (Ubuntu 22.04, Debian 12, Fedora 35, RHEL 9, SteamOS 3 and newer)
OpenSE4-0.6.0-SHA256SUMS.txt	SHA-256 checksums of the three downloads

Every download holds three programs:

• the game (opense4);
• the dedicated server for network and play-by-e-mail games (opense4-server);
• a data checker (opense4-datacheck).

Libraries, our own fonts, the manual and the lessons are built in. The game needs a GPU with Vulkan or OpenGL 3.3.

Running it

• Windows: run the installer, then start OpenSE4 from the Start menu, or unpack the zip and run opense4.exe. Neither is code-signed yet, so Windows SmartScreen may warn the first time ("More info", then "Run anyway").
• Linux: unpack and run ./opense4, or run ./install-desktop-entry.sh once to start it from your desktop's application list.

The game looks for a Steam install of Space Empires IV Deluxe. See README.md for other locations and command-line options (opense4 --help).

Known limitations

• This is still an early build, marked as a pre-release.
• Smaller differences in how the computer players play are still being measured. They fight more decided battles away from colonies, take fewer enemy colonies, and have about one ship fewer at turn 50. They also explore a little less in the first 25 turns.
• Windows builds are tested in CI and under Wine. The executables aren't code-signed.
• In network and e-mail games, every battle is resolved strategically, as in the original.

License

OpenSE4 is free software under the GNU General Public License, version 3 or later. The Noto Sans fonts are under the SIL Open Font License. THIRD_PARTY_NOTICES.txt in each download lists the bundled libraries and their licences.